Method and apparatus for level shifting

1. An apparatus for providing an output voltage comprising: an output circuit being adapted for outputting an output signal having a first signal range, said output circuit comprising a first part and a second part, each of said first part and second part having an input terminal, wherein said first signal range being between a third voltage level and a fourth voltage level; and at least one input circuit, said at least one input circuit being adapted for inputting an input signal having a second signal range and at least a two-level strobe voltage, said input signal comprising at least a two-level input voltage, and second signal range being lower than said first signal range, said at least one input circuit being further adapted for setting a first at least one of said input terminals to a voltage level related to said input voltage when a strobe voltage is set to a first voltage level, aid said input circuit being further adapted for electrically isolating a second at least one of said input terminals when said strobe voltage is set to a second voltage level, wherein said second at least one of said input terminals may include said first at least one of said input terminals, said at least one input circuit further comprises a switch, said switch having a first end connected to said third voltage level and a second end connected to a third at least one of said input terminals and said switch being adapted for setting said third at least one of said input terminals to said third voltage level when the switch is active and a one-way conducting element, said one-way conducting element connected to said third at least one of said input terminals and to said second end of said switch and said one-way conducting element being adapted for setting said third at least one of said input terminals to a voltage level lower than said third voltage level when said switch is inactive, wherein said third at least one of said input terminals may include one of said first at least one of said input terminals and said second at least one of said input terminals.

2. The apparatus as recited in claim 1 , wherein said first part and said second part arm electrically complementary.

3. The apparatus as recited in claim 1 , wherein said voltage levels set on said input terminals are selected such that when said input voltage is set to a first voltage level, a first at least one of said first part and said second part of said output circuit is active, and when said input voltage is set to a second voltage level, a second at least one of said fist part and said second part of said output circuit is non-active, wherein said second at least one of said first part and, said second part of said output circuit may include said first at least one of said first part and said second part of said output circuit.

4. The apparatus as recited in claim 1 , wherein said output circuit generates an output voltage.

5. The apparatus as recited in claim 4 , wherein said output voltage is level shifted with respect to said input voltage.

6. The apparatus as recited in claim 1 , wherein said output circuit is connected to said third voltage level and said fourth voltage level, said third and fourth voltage levels being different.

7. The apparatus as recited in claim 1 , wherein said first part of said output circuit is a floating PDMOS transistor and said second part of said output circuit is a non-floating NDMOS transistor.

8. The apparatus as recited in claim 1 , wherein said at least one input circuit further comprises: a first subcircuit, said first subcircuit being active when said input voltage is set to said second voltage level and said strobe voltage is set to said first voltage level and is non-active otherwise; and a second subcircuit, said second subcircuit being active when both said input voltage and said strobe voltage are set at said first voltage level and are non-active otherwise.

9. The apparatus as recited in claim 8 , wherein said first and second subcircuits being connected between said third voltage level and said fourth voltage level.

10. The apparatus as recited in claim 8 , wherein said at least one input circuit further comprises: a switch circuit, said switch circuit including said switch and one-way conducting element and a switch circuit output, said switch circuit output being connected to one of the input terminals of said first and second parts, said switch circuit connecting said switch circuit output to said third voltage level when said first subcircuit is active, and said switch circuit sets said switch circuit output to a fifth voltage level when said second subcircuit is active.

11. The apparatus as recited in claim 10 , wherein when said switch circuit output is connected to said third-voltage level, said one of said first and second parts having an input terminal connected to said switch circuit in a non-active state, and when said switch circuit output is set to a fifth voltage, said one of said first and second parts having said input terminal connected to said switch circuit in an active state.

12. The apparatus as recited in claim 11 , wherein said switch circuit output is electrically isolated from said one of said first and second parts having said input terminal connected to said switch circuit when said first and second subcircuit are non-active.

13. The apparatus as recited in claim 10 , wherein said first subcircuit and said second subcircuit comprising a concatenation of a PMOS transistor, with its gate connected to its drain and a NDMOS transistor, with its gate being the input of said subcircuit.

14. The apparatus as recited in claim 10 , wherein the input of said first subcircuit is a logical AND of the logically inverted input voltage and the strobe voltage.

15. The apparatus as recited in claim 14 , wherein the input of said second subcircuit is a logical AND of the input voltage and the strobe voltage.

16. The apparatus as recited in claim 15 , wherein said switch circuit comprises a first switch controlled by the input provided by said first subcircuit, a first end of said first switch being connected to said third voltage level, and said switch circuit further comprising a one-way conducting element, a first end of said element being connected to the second end of said first switch, a second end of said element being connected to the input provided by said second subcircuit, said second end of said first switch and said first end of said element being said switch circuit's output.

17. The apparatus as recited in claim 16 , wherein said first switch is a PMOS device, with its gate being controlled by the input provided by said first subcircuit.

18. The apparatus as recited in claim 16 , wherein said one-way conducting element is a diode.

19. The apparatus as recited in claim 16 , wherein said one-way conducting element is a PMOS transistor, with its gate connected to its source.

20. The apparatus as recited in claim 10 , further comprising a second and third switch and a circuit, controlling said second and third switch, a first end of said second switch being connected to said third voltage level, a second end of said second switch being connected to the input provided by said first subcircuit to said switch circuit, a first end of said third switch being connected to said third voltage level, a second end of said third switch being connected to the input provided by said second subcircuit to said switch circuit, said circuit closing said second and third switches when the input terminal of said output circuit is connected to said switch circuit's output and is electrically isolated from said at least one input circuit.

21. The apparatus as recited in 20 , wherein said second and third switches are PMOS transistors with-their gate being connected to said circuit.

22. The apparatus as recited in claim 20 , wherein said circuit is a concatenation of two PMOS transistors, with their gate connected to their drain and a NDMOS device, with its gate connected to said strobe voltage.

23. The apparatus as recited in claim 1 , using CMOS transistors.

24. The apparatus as recited in claim 1 , said first and second parts being electrically equivalent.

25. The apparatus as recited in claim 24 , wherein said at least one input circuit comprises: a first input circuit, said first input circuit being connected to one of said first at least one of said input terminals and said second at least one of said input terminals, said first input circuit being adapted for providing to the one of said first at least one of said input terminals and said second at voltage when said strobe voltage is set to a first voltage level and being further adapted for electrically isolating the one of said input terminals when said strobe voltage is set to a second voltage level; and a second input circuit, said second input circuit being connected to the other of said first at least one of said input terminals and said second at least one of said input terminals, said second input circuit being adapted for providing to the other of side first at least one of said input terminals and said second at least one of said input terminals a sixth voltage level related to said input voltage when said strobe voltage is set to a first voltage level and being further adapted for electrically isolating the other of said first at least one of said input terminals and said second at least one of said input terminals when said strobe voltage is set to a second voltage level.

26. The apparatus as recited in claim 25 , wherein both said fifth voltage level related to said sixth voltage level related to said input voltage are selected such that when said input voltage is set to said first voltage level, both said first and second parts of said output circuit are active, thereby setting a driving circuit in a conducting mode, and when said input voltage is set to said second voltage level, both said first and second parts of said output circuit are non-active, thereby setting said driving circuit in non-conduction mode, wherein said driving circuit includes said output circuit and further includes said at least one input circuit.

27. The apparatus as recited in claim 26 , wherein said output voltage is related to said third voltage level wherein said driving circuit is in conducting mode and electrically isolated from said third voltage level when said driving circuit is in non-conducting mode.

28. The apparatus as recited in claim 24 , wherein each of said first input circuit and second input circuit is connected at one side to said third voltage level.

29. The apparatus as recited in claim 24 , wherein said first part and said second part are a floating PDMOS device in series with a diode.

30. The apparatus as recited in claim 28 , wherein at least one said first input circuit and said second input circuit comprises two subcircuits, said two subcircuits being connected in between a fourth voltage level and the side of the output circuit controlled by said input circuit which is not connected to said third voltage level.

31. The apparatus as recited in claim 1 , said input circuit is adapted for storing the value of voltage at one of said input terminals when said storage voltage is set to said second voltage level.

32. The apparatus as recited in claim 1 further comprises: a cholesteric liquid crystal display; and a driving circuit, said driving circuit for driving said cholesteric liquid crystal display, wherein said driving circuit includes said output circuit and further includes said at least one input circuit.

33. The apparatus as recited in claim 1 , wherein the at least one of said input terminals is electrically isolated from the entire input circuit when said strobe voltage is set to said second voltage level at the at least one input circuit.

34. An apparatus for providing an output voltage comprising: an output circuit comprising a first part and a second part, each of said first part and second part having an input terminal, said first and second parts being subcircuits; and at least one input circuit, said input circuit being adapted for inputting at least a two-level input voltage and at least a two-level strobe voltage, said input circuit being adapted for setting a first at least one of said input terminals to a voltage level related to said input voltage when a strobe voltage is set to a first voltage level, and said input circuit being further adapted for electrically isolating a second at least one of said input terminals when said strobe voltage is set to a second voltage level, wherein said second at least one of said input terminals may include said first at least one of said input terminals, said at least one input circuit further comprises a switch said switch having a first end connected to said third voltage level and a second end connected to a third at least one of said input terminals and said switch being adapted for setting said third at least one of said input terminals to said third voltage level when the switch is active; and a one-way conducting element, said one-way conducting element connected to said third at least one of said input terminals and to said second end of said switch and said one-way conducting element being adapted for setting said third at least one of said input terminals to a voltage level lower than said third voltage level when said switch is inactive, wherein said third at least one of said input terminals may include one of said first at least one of said input terminals and said second at least one of said input terminals.

35. The apparatus as recited in claim 34 , wherein said first part and said second part are electrically complementary.

36. The apparatus as recited in claim 34 , wherein said first part of said output circuit is a floating PDMOS transistor and said second part of said output circuit is a non-floating NDMOS transistor.

37. The apparatus as recited in claim 34 , using CMOS transistors.

38. The apparatus as recited in claim 34 further comprises: a cholesteric liquid crystal display; and a driving circuit, said driving circuit for driving said cholesteric liquid crystal display, wherein said driving circuit includes said output circuit and further includes said at least one input circuit.

39. The apparatus as recited in claim 34 , wherein the at least one of said input terminals is electrically isolated from the entire input circuit when said strobe voltage is set to said second voltage level at the at least one input circuit.

40. An apparatus for providing an output voltage comprising: an output circuit comprising a first part and a second part, each of said first part and second part having an input terminal, wherein either of said first part or said second part being active; and at least one input circuit, said input circuit being adapted for inputting at least a two-level input voltage and at least a two-level strobe voltage, said at least one input circuit being adapted for setting a first at least one of said input terminals to a voltage level related to said input voltage when a strobe voltage is set to a first voltage level, and said input at least one input circuit being further adapted for electrically isolating a second at least one of said input terminals when said strobe voltage is set to a second voltage level, wherein said second at least one of said input terminals may include said first at least one of said input terminals, said input circuit further comprises a switch, said switch having a first end connected to a third level and a second end connected to a third at least one of said input terminals and being adapted for setting said third at least one of said input terminals to said third voltage level when the switch is active and a one-way conducting element, said one-way conducting element connected to said third at least one of said input terminals and said second end of said switch and being adapted for setting said third at least one of said input terminals to a voltage level lower than said third voltage level when said switch is inactive, wherein said third at least one of said input terminals may include one of said first at least one of said input terminals and said second at least one of said input terminals.

41. The apparatus as recited in claim 40 , wherein said first part and said second part are electrically complementary.

42. The apparatus as recited in claim 40 , wherein said first part of said output circuit is a floating PDMOS transistor and said second part of said output circuit is a non-floating NDMOS transistor.

43. The apparatus as recited in claim 40 , using CMOS transistors.

44. The apparatus as recited in claim 40 further comprises: a cholesteric liquid crystal display; and a driving circuit, said driving circuit for driving said cholesteric liquid crystal display, wherein said driving circuit includes said output circuit and further includes said at least one input circuit.

45. The apparatus as recited in claim 40 , wherein the at least one of said input terminals is electrically isolated from the entire input circuit when said strobe voltage is set to said second voltage level at the at least one input circuit.

46. An apparatus for providing an output voltage comprising: an output circuit comprising a first part and a second part, said first part including an input terminal and a first output connection, and said second part including an input terminal and a second output connection, and said output circuit having said first and second output connections connected together thereby defining an output voltage, and said output circuit is further connected to a third voltage level and a fourth voltage level, said third voltage level being different from said fourth voltage level and said output voltage being at one of said third voltage level and said fourth voltage level; and at lest one input circuit, said at least one input circuit being adapted for inputting at least a two-level input voltage and at least a two-level strobe, said at least one input circuit being further adapted for setting a first at least one of said input terminals to a voltage level related to said input voltage when a strobe voltage is set to a first voltage level, and said at least one input circuit being further adapted for electrically isolating a second at least on of said input terminals when said strobe voltage is set to a second voltage level, wherein said second at least one of said input terminals may include said first at least one of said input terminals, said input terminals, said input circuit further comprise: a switch, said switch having a first end connected to said third voltage level and a second end connected to a third voltage level and a second end connected to third at least one of said input terminals and being adapted for setting said third at least one of said input terminals to said third voltage level when the switch is active and a one-way conducting element, said one-way conducting element connected to said third at least one of said input terminals and to said second end of said switch and being adapted for setting said third at least one of said input terminals to a voltage level lower than said third voltage level when said switch is inactive, wherein said third at least one of said input terminals may include one of said first at least one of said input terminals and said second at least one of said input terminals.

47. The apparatus as recited in claim 46 , wherein said first part and said second part are electrically complementary.

48. The apparatus as recited in claim 46 , wherein said first part of said output circuit is a floating PDMOS transistor and said second part of said output circuit is a non-floating NDMOS transistor.

49. The apparatus as recited in claim 46 , using CMOS transistors.

50. The apparatus as recited in claim 46 further comprises: a cholesteric liquid crystal display; and a driving circuit, said driving circuit for driving said cholesteric liquid crystal display, wherein said driving circuit includes said output circuit and further includes said at least one input circuit.

51. The apparatus as recited in claim 46 , wherein the at least one of said input terminals is electrically isolated from the entire input circuit when said strobe voltage is set to said second voltage level at the at least one input circuit.